The invention relates to a method for producing a multilayer element having a carrier ply and a single-layer or multilayer decorative ply formed on and/or in the carrier ply, and also to a multilayer element obtainable accordingly.
Optical security elements are frequently used in order to hinder the copying of documents or products in order to prevent their misuse. Thus optical security elements find use in securing documents, bank notes, credit cards, money cards, identity papers, high-value product packaging and the like. Known in these contexts is the use of optically variable elements as optical security elements which cannot be duplicated by conventional copying methods. Also known is the furnishing of security elements with a structured metal layer which is designed in the form of a text, logo or some other pattern.
Generating a structured metal layer from a metal layer applied two-dimensionally by sputtering or vapor deposition, for example, requires a multiplicity of operations, particularly if the intention is to generate fine structures which exhibit high anticounterfeit security. Thus it is known, for example, that a metal layer applied over the full area can be partially demetallized and thereby structured by means of positive or negative etching or by means of laser ablation. As an alternative to this it is possible to apply metal layers already in structured form to a carrier, by use of vapor deposition masks.
The greater the number of manufacturing steps in the production of the security element, the greater the importance accorded to the register accuracy of the individual method steps, i.e., the accuracy in positioning of the individual tools relative to one another during the formation of the security element, in relation to structures or layers or features already present on the security element.